Improvement in pressure-gauges



H. CHWATAL Pressure Gage.

Patented April12, 1870- N. PETERS, PNOTO-LITNOQRAPIIER, WASHINGYON D Cdint-toil tatrs v aunt diflfiire.

HERMAN OHWATAL, OF NEW YORK, N. Y., ASSIGNQR TO W. STAEHLEN, AND L.PORTONG.

Letters Patent No. 101,832, dated April 12, 187 (mtedatezl April 2,1870.

IMPROVEMENT IN PRESSURE-GAUGES.

The Schedule referred to in these Letters Patent and making part of thesame.

To all whom it may concern Be it known that I, HERMAN CHWATAL, of thecity, county, and State of New York, have made certain new and usefulImprovements in Dial-pressure and Vacuum-spring Gauges; and I do herebydecla re that the following is a full, clear, and exact description ofthe construction and operation of the same, reference being had to theaccompanying drawings and letters of reference marked thereon, theymaking part of this specification.

The nature of this invention consists in the peculiar arrangement andconstruction of the crank or eccentric upon the hand-arbor, used fortransmitting the motion to the hand, it being constructed in a manner toadjust the crank-pin with great precision, and to adjust it while andwith the working-parts together, ready for operation. By these means thegauge can be set very accurately, and is prevented from soon becomingdefective in accuracy.

To enable others skilled in the art to make and use my improvements, Iwill proceed to describe their construction and operation in detail.

In the annexed drawings- Figure 1 is a vertical central section of thegauge with my improvements.

Figure 2 is a face-view of the same, the dial shown removed andrepresented in red outline-s.

Figure 3 is a detached vertical section of my improved adjustable leveror crank on an enlarged scale.

Figure 4 is a side view of the same.

Figure 5 is a face-view of a modification of the said lever or crank.

Similar letters of reference indicate corresponding parts in the severalfigures.

A represents the usual circular case;

B, the dial;

0, the hand;

D; the usual corrugated circular spring of the gauge; and

E, the flange-ring, by means of which the spring is secured.

F is the ordinary right-angular armed lever, which has its fulcrum inthe upper end of the plate G, and bears with the one arm upon thecentral portion of the spring, while the other arm serves to transferits motion received from the spring to the hand of the instrument. v

H represents the arbor upon which the hand is secured, and it'isprovided with a slotted crank or lever, I, which has an adjustablecrank-pin, J, working in the slot K of the said crank, and arranged withits arbor, so that the said pin can be adjusted and set to any minutedistance from the center of said arbor with great precision. For thislatter purpose I securethe said crank-pin in a block, L, fitted withgreat precision to slide in the slot K of the crank, and provide thesaid crank with a feed-screw, M, arranged parallel with its slot, fittedwith its screw-thread in the rear portion of the said block I, andhaving its bearings accurately fitted, side and endwise, guided in therear projections N N of the said crank.

In order to turn the said feed-screw, I make square its projecting end,and have, in order to guide it endways, proper shoulders formed on it tofit against its bearings.

It will be seen, by means of the feed-screw M, the said block L and thecrank-pin fitted therein are made adjustable with the desired precisionto the motion of the spring, corresponding with the desired indicatingscale of pressure.

The plate G is secured to the flange-ring E of the mainsp'i-ing of thegauge, by means of the screw 0, and the aperture through which saidscrew 0 passes is slotted, in order to adjust the said platewith morefacility, and to save labor in manufacturing them in quantity.

1? represents a coiled hair-spring, usually employed in these gauges fortaking up the lost motion of the working-parts, and to give the hand asteady and positive movement. It is secured with one end in the post Qupon'thc flange-ring E, while its other end is attached with the crankof the m nd-arbor.-

By means of the rod R, the crank-pin J and, lever F are connected, andthereby the motion of the mainspring of the gauge transferred to thehand-arbor and hand.

From the foregoing it will be seen that, by employment of theabove-mentioned working-mechanism, the construction of the gauge isgreatly simplified and its production economized, its durability andservice made more certain and accurate, which. advantages are of greatimportance to the public.

Having fully described my invention,

What claim therein, and desire to secure by Letters Patent, is-

In steam and other pressure and vacuum-gauges, the employment of thecrank I, when provided for adjusting the pin J of said crank withthe-screw M and sliding block 1., substantially as and for the purposeherein shown.

H. CHWATAL. .Witnesses A. Bnnssrn, J. ROSENGAK s.

